呼吸衰竭的发病机制主要有（）
A.通气不足
B.通气血流比值失调
C.弥散功能障碍
D.营养不良
E.呼吸浅速
参考答案：A, B, C
流动比率用来判断企业短期债务到期前，可以转化为现金用于偿还流动负债的能力。国际上公认标准比率为( )。
A．100%B．150%C．180%D．200%
Password is a secret series of (69) that enables a user to access a file, computer, or program. On multi-user systems, each user must enter his or her password before the computer will respond to (70) . The password helps ensure that (71) users do not access the computer. In addition, data files and programs may require a password.
A．order
B．commands
C．instruction
D．tracks
